Kohler 1.28 vs 1.6 GPF Toilets | Comparison

Choosing the perfect toilet for your space can be quite a challenge, as they all appear to be quite similar at first glance. However, upon closer inspection, you’ll notice that each individual element, such as height, shape, and flushing system, plays a critical role in distinguishing one toilet from another.

The most significant distinguishing factor between toilets is the amount of water used during each flush, with capacities ranging from 1.28 to 0.8 gallons per flush (GPF). This means that toilets use either 1.6 or 0.8 gallons of water per flush.

Interestingly, a toilet that uses 1.6 to 1.28 GPF per flush can effectively flush down up to 900 grams of solid waste in a single flush, while also conserving water.

In this post, our aim is to provide you with a comprehensive comparison of Kohler’s 1.28 GPF versus 1.6 GPF toilets. We’ll cover all of the essential aspects that every buyer should consider, including functionality, durability, genuine customer reviews, and user experience.

1.28 vs 1.6 GPF Kohler Toilets: Product Review

Kohler K-3589-0 Elongated 1.6 GPF Toilet

Kohler K 3589 0 Elongated 1.6 GPF Toilet

The Kohler K-3589 toilet is designed to offer optimal comfort during use, thanks to its two-piece structure that includes an elongated bowl. With this toilet, you can enjoy a more spacious and comfortable experience.

One of the key features of this toilet is its chair-height seating, which makes it easy for most adults to sit and stand up without any hassle. Additionally, its sleek design makes it stand out in any bathroom.

While it’s worth noting that the seat and supply line aren’t included with the toilet, the K-3589-0 still boasts impressive performance. It’s a combination of the Kohler-4309 bowl and Kohler-4418 tank, and features Aquapiston technology that ensures accurate distribution of water during flushing.

Overall, the Kohler K-3589 toilet is a top choice for anyone seeking a comfortable, efficient, and stylish toilet for their bathroom.

Why we recommend this:

  • An elongated bowl providing comfort.
  • The right height making sitting and standing easy.
  • An efficient and effective flushing system.
  • Low consumption of water.
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Kohler K-3609 – 1.28 GPF Cimarron Comfort Height Toilet

Kohler K 3609 – 1.28 GPF Cimarron Comfort Height Toilet

Indulge in luxurious comfort with this elongated bowl toilet, providing ample seating space for added comfort. Designed with ease of use in mind, this toilet boasts a height that’s perfect for adults with back problems, making sitting and standing a breeze.

Not only is this toilet comfortable, but it also helps you save water. With its low water consumption rate of 1.28 gallons per flush, you’ll be saving money and doing your part for the environment.

Efficient and effective flushing is guaranteed with the innovative Aquapiston technology, leaving your bowl spotlessly clean after every use.

Making your bathroom routine even easier is the polished chrome trip lever on the left-hand side, providing a convenient and stylish finishing touch.

Why we recommend this:

  • Low consumption of water at 1.28gpf.
  • Comfort with elongated bowl.
  • Aquapiston technology making the flushing system effective.
  • The right height of the toilet.
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Comparison Table

FeaturesKohler 1.28 GFP
Kohler 1.6 GFP
Water Consumption:1.28 Gallons Per Flush1.6 Gallons Per Flush
Powerful Flush:NoYes
Flush typeGravity flushGravity flush
Space Saving:YesNo
Bowl After Flush:CleanMarginally Cleaner

 Final Verdict

When it comes to finding the perfect toilet for your needs, it’s important to choose one that not only delivers quality and durability, but also provides innovative features that add value to your purchase. Look no further than Kohler, a brand renowned for its exceptional standards in these areas.

Kohler toilets are designed with your comfort in mind, offering optimal seating height that makes sitting and standing a breeze. Additionally, the rough-in measurements are perfectly suited for your bathroom, ensuring a seamless fit.

One of the standout features of Kohler toilets is their use of Aquapiston technology in the flushing system. With just a single flush, you can be sure that the bowl will be left sparkling clean, while using minimal water.

To ensure compliance with industry standards and reduce your water bills, Kohler has made sure that each of their toilets has a controlled flow rate between 1.28 and 1.6 gallons per flush.

While each model may have its own pros and cons, rest assured that with Kohler, you can expect only the best. Take the time to consider the features that matter most to you, and choose the toilet that meets all of your needs in the long run.

Kohler Elongated 1.6 GPF Toilet

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ir?t=kivia02 20&language=en US&l=li3&o=1&a=B002I0GRRAMore powerful to flush heavier toilet waste in a single flush.”

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KOHLER Cimarron 1.28 GPF Toilet

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ir?t=kivia02 20&language=en US&l=li3&o=1&a=B002DP4D08Environmental friendly toilet – saves more water per single flush up to 3000-4500 gallons of water per year.”

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Selecting the ideal toilet for your home should be a breeze since you already have a clear idea of your requirements and preferences. To determine which toilet will be the most suitable for your bathroom, consider the following features of these two options.

Firstly, efficiency is a crucial aspect to consider. Ensure that the toilet you select consumes less water and is eco-friendly. Additionally, the effectiveness of the toilet should be evaluated, as it should be able to flush away waste easily without clogging.

Comfort is another significant factor to consider. You should select a toilet that provides optimal comfort and convenience, particularly if you intend to use it frequently.

Choosing the right toilet can bring numerous advantages to you and your loved ones, such as a hygienic and comfortable experience, as well as saving money on water bills.

Interested in more options for your Bathroom? Our Best Quite Flush Toilet Review is another helpful resource.

How can I make my low flow toilet flush better?

Is your toilet having an issue with flushing the bowl well? Leaving smudges on the bowl surfaces making you wait to flush again to have it clean?

This could make it challenging to have a clean toilet and wastewater as you have to flush more than once to have a clean bowl. There are certain things you could adapt to make your low flow toilet flush better, letting you improve on the flushing of the whole toilet.

First: check whether your toilet may be clogged. This could be done simply by pouring a bucket into your toilet bowl and flushing it.

A clogged toilet would not flush. Have the clogged toilet unclogged with the use of a plunger or a snake. Proceed to do the experiment again to check whether you have unclogged your toilet.

Second: Lift the tank cover. Inspect the water level in the tank to check whether the water is at the required level.

In the case where your water level is not in the right position, make use of the tank float assembly which is found in your toilet tank to have the water adjusted accordingly.

Third: around the rim of your toilet bowl, there are flush holes located, have them checked. Some of the flush holes may be clogged making the water into the bowl low in concentration leading to a decrease in pressure.

Make use of a small drill bit or a coat hanger and push it through the holes to clear any blockage that may be present. Proceed to flush to see if there is an improvement in the water pressure.

Fourth: make use of bleach to have your toilet cleaned. First, proceed to have your water supply to the tank switched off on the water supply valve.

Switch off the valve to have the water completely stopped from supplying water. Pour half a liter of bleach to your toilet bowl and let it sit for 20 minutes at the most.

After 20 minutes, proceed to flush the toilet allowing the bleach to work through the toilet system cleaning out the blockage.

This will see the cleaning of your toilet getting rid of all the blockages and reducing the inefficiency of your low flush toilet.

Fifth: the easiest of them all is to have your toilet soaked in vinegar to improve on the flush power of your toilet. Have the lid to your toilet tank opened, removing carefully the fill hose at the top of the overflow tube.

Using a funnel pour a quart of vinegar into the tube. Let the vinegar sit for a minimum of two hours.

This will help with the disinfection and the relieving of the deposits that build up with time your toilet system.

The five steps above will help with the improvement of your flushing power of your toilet n the overall and should be repeated when you are having an issue with your toilet.

In the case where the steps may not work or be effective, you may consider having your toilet replaced.

What does 1.6gpf toilet mean?

1.6gpf toilet simply means the consumption per flush by the particular toilet stands at 1.6 gallons in a single flush.

Toilets are referred in regard to the consumption of water in a single flush to make you aware of how much the toilet will consume when you flush.

Different toilets have different consumption with each working on their efficiency to ensure the toilet bowl is exceptionally clean.

Is a one-piece toilet better than a two-piece toilet?

Toilets offer different features from the shape, color, and size. When deciding on the toilet that will serve you perfectly you need to decide on whether the toilet you are going for is either a one-piece toilet or a two-piece toilet.

A clear understanding of how they function will assist you in making the decision.

Each water closet is made of 3 crucial parts which are the tank, bowl, and pedestal.

The pedestal takes note of the height being optimal, while the tank caters for the water storage that is essential for flushing power to maintain the cleanliness of the bowl.

The bowl not only collects the wastes but sees the waste to the drain line.

The one-piece toilet also the traditional piece, as the bowl and the tank fused with no joints available. The two-piece toilet is constructed in a way the tank and the bowl are separate and would be put together with fittings.

The two toilets are known to function optimally with their performance being on the same level.

The choice you make on the particular toilet you go for will entirely be dependent on the budget, personal preferences, and individual needs.

Below are some of the facts you should have of each particular toilet.

Performance & Functionality

The functionality and performance of these two toilets do not differ in any way. These two toilets offer similar efficiency and power with the functionality of the two toilets being dependent on the design and the flushing mechanism.

This is expected as most of the interior parts are identical and manufactured by the same company.

You may be in favor of the water-saving or the comfort in height; these could be found in either of the pieces without compromise on its functionality and performance.

Ease of Installation

The installation process of each toilet has its benefits and its drawbacks. The installation is similar for both of the toilets but t tales less time to have a one-piece toilet installed.

Despite this fact, it may be challenging getting it in the right position. Having a one-piece in the right position may need a lot of practice and effort if you choose to do it by yourself.

The benefit of having a two-piece toilet installed is that you will be moving two light-weight pieces, unlike the one-piece toilet. This makes it easier to carry the toilet around and to fix it in the right position.

You ought to have in mind that a two-piece toilet will need a second installation process as you will need to have the two pieces functioning as a unit. Be careful not to break the porcela

in tank in a 2-piece toilet.

Ease of Cleaning

The need to have a clean toilet with low effort and minimal maintenance is something we all seek.

This pushes people to go for the one-piece toilet as it gives an easier time to clean as there are no joints between the bowl and the tank.

A one-piece toilet has a skirted bowl with a flat exterior surface.

This molded design translates to no grooves in between thus less space for grime to settle in. this sees the prevention of growth and spread of bacteria.

This makes a one-piece toilet ore hygienic and thus easy to maintain. The two-piece toilet on the other hand has more hard to reach spaces thus hard to clean. The joint area in a two-piece toilet offers a favorable ground for dirt ad bacteria to grow and settle.

Size & Weight

The two-piece and the one-piece toilet both come in different sizes depending on your preference. The one-piece model is known to consume less space due to the design they adopt.

The molding of the tank and the bowl together makes sure the space taken up is less.

The most common feature on the one-piece toilet offer are the comfortable height with the bowl sitting at 17”. The one-piece toilets are known to be heavier as it is molded into one piece.

On the other hand, the two-piece toilets will give you a comfortable and the standard height of your toilet making it suitable for all bathrooms available.

When in search of a toile be sure to take note of the rough-in, which refers to the distance between the walls behind your toilet to the center of the drain pipe.

The common measurement is 12” rough-in but there are other measurements of 10” to 14”.

The two-piece toilets are known to have more options available regarding the rough-in as they are designed differently to fit different types of bathrooms.

The double piece is known to weigh less as you can separate the bowl from the tank, making it easy to move it around when fixing it.

The Durability

The feature of the single-piece toilet where there is no need to join the part of the toilet thus easy maintenance. This makes the single piece toilet more durable, reliable, and tougher and you will not worry about leakages.

The double piece toilet will need extra care as the bowl and the tank may crack over time. With the breakage of one of the two, you will need to replace one or both of them at some point.

Another issue is the rubber gasket in the double piece toilet which tends to wear out after a period leading to leaks.

Both toilets could last long enough when taken care of in the right way without the need for a replacement.

Aesthetic Look

The double and single-piece toilets offer a wide range of shapes and styles to choose from.

Most individuals go for the single-piece toilet as it is more stylish, its continuous and seamless design with no joints and gaps in between gives it a more stylish look.

It adds a luxury appearance to your bathroom with the skirted bowl giving it a contemporary look.

Advantages of the one-piece Toilet


  • With flushing options, saving on water.
  • Durability and less susceptible to breakages.
  • Smaller sized and compact.
  • Easy and fast installation.
  • Easy to clean options.
  • A Sleek design.
  • A comfortable height to sit.
  • Stylish and unique design.


  • t is heavy.
  • The rough-in options are few.
  • More pricey.

Advantages of the Two-Piece Toilets


  • The rough and height options are many.
  • The bowl or the tank can be replaced separately.
  • Easy to ship across states.
  • They are cheaper compared to the one-piece toilets.
  • Easy installation process.
  • The style compliments different ideas of your bathroom.


  • More susceptible to breakages and leaks.
  • Difficulty in cleaning and maintaining.
  • The installation is time-consuming.
  • Its height would not work with short individual.

How much water does a low flow toilet use

The toilets invented in the 1980s saw the consumption of water u to 3.5 gallons in a single flush.

This was an improvement from the original toilets which saw consumption of up to 5 to 7 gallons in a single flush.

Taking into consideration where the average person flushes 5 times in a single day this will see a high consumption of water to be particular in a household with several individuals.

Gradually there has been an improvement on every toilet that was manufactured since 1994 with a consumption of 1.6 gallons per flush with a newer version seeing consumption of 1.28 gallons per flush.

At the beginning, these models received back lush for not performing exceptionally as the earlier model, but with time the low-flush toilet improved with the inclusion of new technologies.

A household with several individuals will save several thousand gallons in a year with the simple switch to a low-flush toilet.

What does a concealed trap way mean?

A lot of people are going for toilets that offer the needed aesthetic in their bathroom. They all end up looking at the concealed trapway toilets which could be vividly explained.

The toilets with concealed trapway offer an integrated, skirted base that provides a cleaner and sleeker aesthetic. dual flush toilet

The concealed trapway toilets fit perfectly in homes gong for seamless design elements in the home, with time the toilet designs are getting more contemporary, simpler, and sleeker.

Concealed trapway toilets are time-consuming in the engineering work and the details on the toilet, making it more costly compared to the standard toilet.

In case you are in search of style and design, this toilet will be the right one to go for.

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What does GPF stand for in Kohler toilets, and why is it important?

GPF stands for “Gallons Per Flush.” It refers to the amount of water a toilet uses for a single flush. The two common GPF options in Kohler toilets are 1.28 GPF and 1.6 GPF.

The difference in GPF affects water consumption, with 1.28 GPF using less water than 1.6 GPF. This distinction is essential for water conservation, as lower GPF models save more water with each flush, contributing to environmental sustainability and reduced water bills.

Are there any advantages of choosing a Kohler 1.28 GPF toilet over a 1.6 GPF model?

Yes, opting for a Kohler 1.28 GPF toilet offers several advantages. Firstly, it is more water-efficient, using about 20% less water per flush compared to a 1.6 GPF toilet.

This eco-friendly feature helps conserve water, benefitting the environment. Secondly, many regions and cities have water usage regulations that favor lower GPF toilets, making the 1.28 GPF option compliant with such requirements.

Additionally, a 1.28 GPF toilet can lead to cost savings on water bills over time, especially in households with frequent toilet usage.

Is there any significant difference in flushing performance between Kohler 1.28 GPF and 1.6 GPF toilets?

Despite using less water, Kohler 1.28 GPF toilets are engineered to deliver powerful and efficient flushing performance. Kohler incorporates advanced technologies, such as AquaPiston or Class Five flushing systems, to ensure effective waste removal and bowl cleanliness with each flush.

Customers can expect comparable flushing performance between the two GPF options, as Kohler takes care to maintain high-quality standards in all its products.

Can I upgrade my existing Kohler 1.6 GPF toilet to a 1.28 GPF model without replacing the whole toilet?

In many cases, you can convert your existing Kohler 1.6 GPF toilet to a 1.28 GPF model without replacing the entire unit. Kohler offers retrofit kits, which include components like a new flush valve and flapper, designed to transform your toilet into a more water-efficient version.

However, it’s essential to verify compatibility with your specific toilet model and consult the manufacturer’s guidelines or a professional plumber for a successful conversion.

Are Kohler 1.28 GPF toilets more expensive than 1.6 GPF models?

In general, Kohler 1.28 GPF toilets are competitively priced and often not significantly more expensive than their 1.6 GPF counterparts. The difference in cost, if any, is usually minimal and can be offset over time by the water-saving benefits of the 1.28 GPF option.

Additionally, potential water bill savings and environmental benefits make the initial investment worthwhile.

Do Kohler 1.28 GPF toilets meet industry standards and regulations?

Yes, Kohler 1.28 GPF toilets adhere to industry standards and regulations. Most of their models are WaterSense certified, which means they meet or exceed the strict water efficiency and performance criteria set by the Environmental Protection Agency (EPA).

WaterSense certification ensures that the toilets offer optimal flushing performance while using less water, promoting sustainability and water conservation.

Are there any downsides to choosing a Kohler 1.28 GPF toilet?

While Kohler 1.28 GPF toilets are excellent choices for most households, there are a few potential downsides to consider. Some users might find that these toilets have a slightly lower flush power compared to 1.6 GPF models, but advancements in technology have mitigated this concern significantly.

Additionally, certain waste types may require an occasional double flush with lower GPF models, but this is rare and not a major issue in most cases.

How can I maintain and clean my Kohler 1.28 GPF toilet properly?

Maintaining and cleaning your Kohler 1.28 GPF toilet is essential to ensure its longevity and optimal performance. Regularly clean the bowl using a non-abrasive cleaner and a soft brush. Avoid using harsh chemicals or abrasive pads that could damage the glaze.

Periodically inspect the flush valve, flapper, and fill valve for any signs of wear or leakage. If you notice any issues, promptly replace the faulty components with genuine Kohler parts.

Can a Kohler 1.28 GPF toilet be installed in all plumbing systems?

Yes, Kohler 1.28 GPF toilets can be installed in most standard plumbing systems found in residential and commercial buildings. They are designed to fit standard rough-in measurements and work with conventional plumbing setups.

However, if you have a specialized or older plumbing system, it’s advisable to check the specifications and consult a plumber to ensure compatibility before purchasing.

Does Kohler offer a warranty for their 1.28 GPF toilets?

Yes, Kohler provides a limited warranty for their 1.28 GPF toilets, as they do with most of their products. The warranty duration and coverage may vary based on the specific model and region, so it’s crucial to review the warranty terms before making a purchase.

Generally, the warranty covers manufacturing defects and faulty materials for a specific period, giving customers added peace of mind and assurance of product quality.

Kohler 1.28 vs 1.6 GPF Toilets
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